Why does SpawnActor Deferred fail on FinishSpawning?

Construction Script may rely on exposed properties that you haven't set yet. Set required properties before FinishSpawning so Construction has valid input.

Lets you set Expose-on-Spawn properties between SpawnActor and FinishSpawning. Construction Script runs once at FinishSpawning with your provided values.

Differences between Spawn and Spawn Deferred?

Spawn runs Construction with default props. Deferred lets you customize before Construction runs. Use Deferred when you have spawn-only-mutable state.

Fix: SpawnActor Deferred Fails on FinishSpawning

Quick answer: Set Expose-on-Spawn props between SpawnActor Deferred and FinishSpawning. Construction Script runs at FinishSpawning — needs valid props.

Spawn weapon Deferred. Construction Script tries to read WeaponData. WeaponData was unset; spawn errors and actor doesn’t materialize.

The Fix

BP:
  → Spawn Actor From Class (Deferred)(Class=Weapon, Transform)
      out Actor
  → Set WeaponData on Actor
  → Set TeamID on Actor
  → Finish Spawning(Actor)   // Construction Script runs now with valid data

Mark properties as Expose on Spawn so they appear as pins on Spawn Deferred too. Construction reads them deterministically.

Verifying

Spawn weapon. Actor exists with correct data. Without setting between: Construction errors and actor invalid.

“Set in between. Finish creates.”

Related Issues

For Soft Class async load, see soft class. For BP Interface defaults, see BPI defaults.

Set then Finish. Actor lands.